Central to the Program Project are the stocks that have already been created by the Program Director. These are as follows: IV - base stock founded from flies collected in 1975 by P.T. Ives from an endemic Massachusetts population of Drosophila melanogaster; B - five replicates of the base stocks, founded in 1980; O - five populations derived from the IVs, selected for fertility at 10 weeks, founded in 1980; RU, C, and OC - replicated derivatives of the Os that have since undergone selection for early fertility, like Bs, derived in 1985, 1987, and 1989, respectively; D - replicated derivatives of the Os that have undergone selection for increased resistance to desiccation, founded in 1987; SO - replicated derivatives of the Os that have undergone selection for increased resistance to starvation, founded in 1989; SB - replicated derivatives of the Bs that have undergone selection for increased resistance to starvation, founded in 1989; DS - replicated derivatives of the Ds that have undergone selection for resistance to starvation, founded in 1989. The maintenance of these stocks is crucial to the success of all other research projects, both as experimental material and as points of reference for further experiments. The major activities involved include preparation of culture media, handling of flies, and cleaning of culture equipment, primarily glassware. In addition, funds are requested for the communication functions of the project: publication of papers, telecommunications, and travel. These will be allocated from the Core to the individual participants in the Program Project.